Checking the coolant level
The coolant level should be checked regularly - about every 4 weeks, and always before any long trip.
Caution: When the engine is hot, open the cover carefully.
Danger of injury! When opening, put a rag. If possible, open the cap when the coolant temperature is below 20°C.
When opening the cap, first unscrew it a little to release the pressure. Then fully unscrew and remove the cover.
Pre-August 1988 4-cylinder engine: coolant level on cold engine (coolant temperature approx. 20°C) must reach a maximum of 2 cm below the threaded part -1-.
Models 316i September 1988 and 318i September 1987 onwards: coolant level when engine is cold (coolant temperature approx. 20°C) must reach the mark on the expansion tank or be slightly above it (arrow).
Six-cylinder engine: coolant level on a cold engine (coolant temperature liquids around 20°C) should reach the -K- mark.
To avoid damaging the engine, pour cold coolant only into a cold engine.
For topping up - even in the warm season - use only an antifreeze solution in clean, lime-free water.
Attention: On the way, especially in the warm season, topping up with clean water is allowed. However, after this, adjust the concentration of the mixture as soon as possible.
Visually inspect for coolant leaks if the level often falls below the minimum mark.